Nanoemulsions possess powerful nano-scale properties that make them attractive for diverse applications such as drug delivery, food supplements, nanoparticle synthesis and pharmaceutical formulation. Tailorable nanoemulsions (TNEs) have invented as a breakthrough nanomedicine platform. Customised peptide surfactant, AM1 is capable of reversibly and precisely controlling the stability of oil/water emulsions. Thus, TNEs are able to target selected cells like a cell-specific antibody, or immune-evading polyethylene glycol (PEG), spontaneously self-assemble at the oil-water interface in a control manner.
Our aim of this study is to use Coherent Anti-Stoke Raman Spectroscopy (CARS) to assess the enhanced transdermal delivery of TNEs by elongate microparticle (EMP) technology. CARS is a dye-free method which images structures by displaying the intrinsic vibrational contrast of their molecules without damaging samples. CARS system specifically targeted to lipid based molecules from the droplets of TNEs. With this technology, cutaneous delivery of a wide range of lipophilic payloads becomes possible. EMPs are not attached to any solid support allowing application to large areas of skin. Penetration of the stratum corneum by the microparticles creates pathways for the delivery of range of bioactive. We have conducted preliminary experiments where EMPs were dry coated with TNEs. The diameter of combined size became larger by 10% compared to TNEs alone. We dry coated TNEs with a biocompatible polymer, alginate. Images from CARS showed coating was largely successful and stable for at least 72 hours. When this dry form of EMP-TNE was applied to excised human live abdominal skin in real time, EMPs penetrated to dermal-epidermal junction and we observed that the controlled release of TNEs began shortly after administration. Lipids could be detected as deep as 60 µm into the skin confirmed by CARS showing a potential usage of TNEs as a hydrophobic drug carrier. To our knowledge, this is the first study using CRAS imaging system to investigate transdermal drug delivery of nanoemulions release profile off the microparticles in live excised human skin.
In conclusion, the data show that a dry, slow release formulation containing EMPs coated with TNEs can effectively deliver a hydrophobic payload deep into the human epidermis and slowly release that payload in a controlled fashion. This leads to the establishment of new transdermal controlled drug delivery platform.